Windows xp wont boot and keeps restarting.

have u tried the memory card?
if u have 2 memory chips, then check it one by one. if u get the same problem again. try a new or other memory chip same type.

try this one first: remove the hard disk, use an IDE or Sata to USB converter cable. plug the usb in other computer running Vista. when the partition appears right click on it, click 'tools' then check the hard disk for errors only, do not tick for bad sectors option. if there are errors on the hard disk it will fix it. u will be given a report after see in that report that u dont have bad sectors, bad sectors must be 0.

then after that place back the hard disk to your computer and start it again. hope u wont get that message again. if u get then try the first solution, replace the memory.

first try booting in safe mode

last if nothing seems to be working then just reinstall the windows as it seems to be that there is some preoblem with OS.